Denial of service in Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software

1) Improper Enforcement of Message Integrity During Transmission in a Communication Channel

EUVDB-ID: #VU57753

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34793

CWE-ID: CWE-924 - Improper Enforcement of Message Integrity During Transmission in a Communication Channel

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists in the TCP Normalizer when handling certain TCP segments. A remote attacker can send a specially crafted TCP segment through an affected device and poison MAC address tables.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service attack but requires the affected device to be operating in transparent mode.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Cisco Adaptive Security Appliance (ASA): 9.7 - 9.15.1.10

ASA 5500-X Series Firewalls: All versions

Cisco Firepower Threat Defense (FTD): 6.2.0 - 6.7.0

CPE2.3

• cpe:2.3:h:cisco_systems:asa:9.7:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.8.4.35:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.9.2.85:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.10.1.44:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.12.4.18:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.13.1.21:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.14.2.13:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:asa:9.15.1.10:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.2.3.16:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.2.2.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.2.1:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.2.0:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.3.0.6:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.4.0.12:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.5.0.5:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.6.4:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_ftd:6.7.0:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:asa_5500-x_series_firewalls:*:*:*:*:*:*:*:*

External links

http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvx46296
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dos-JxYWMJyL

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.